# Homework Help: Two forces acting on an object

1. Feb 20, 2008

### dflutedevil

Two forces, both in the x-y plane, act on a 1.5 kg mass that accelerates at 7.3 m/s^2 in a direction 30 degrees counterclockwise from the x axis. One force has magnitude 6.8 N and points in the + x direction. Find the other force. Express it as a comma separated pair of components.

I know this seems easy but I'm just not getting it. Any help?

2. Feb 20, 2008

### blochwave

You know mass and acceleration so you can find the resultant net force's magnitude

You know one component of the resultant force is just a vector of magnitude 6.8N at 0 degrees(on the x-axis)

So that vector + another vector you need to find = the resultant vector

You should know equations for deducing both the magnitude and angle of the second vector(they involve trig and right triangles), then you can use trig to get those components.

3. Feb 21, 2008

### dr_d_is_cool

if it involves trig then of course it involves right angles